Abstract WP165: Thyroid Function is Associated With Stroke Severity, Discharge Outcomes, and Quality of Life After Ischemic Stroke

Abstract

Objective: Data regarding the relationship between thyroid function and ischemic stroke (IS) are conflicting and limited by small sample sizes. In a large prospective cohort, we evaluated whether thyroid function at index hospitalization is associated with stroke severity or functional outcomes. Methods: Consecutive patients with IS were enrolled in observational cohort study which prospectively collected demographic (age, sex, race, insurance), clinical (NIHSS score, baseline function, risk factors, TOAST subtype), imaging (infarct volume), hospital treatments, and outcome data at 3 months. Thyroid stimulating hormone (TSH) levels upon admission were captured from the Enterprise Data Warehouse. Outcomes included discharge ambulation and modified Rankin Scale (mRS) and Neuro-QOL upper extremity, lower extremity, and cognition T-scores at 3 months. We assessed the association between TSH (log transformed and quartiles) levels and discharge and 3-month outcomes using bivariate and multivariate linear and logistic regression, as appropriate. Results: Among 559 patients (mean age 64.5±15.9 years; 51.2% male; 31.3% black; 8.4% Hispanic), TSH values were correlated with age (r s =0.115, p=0.007), initial NIHSS score (r s =-0.097, p=0.022) but not infarct volume (r s =-0.054, p=0.227). The lowest quartile of TSH (<1.02 mU/L) was associated with black race (42.6 vs. 27.5%, p=0.001), non-Medicare status (61.7 vs. 51.9%, p=0.044), and non-ambulatory status at discharge (38.3 vs. 28.5, p=0.029). In multivariate analyses adjusting for baseline mRS, initial NIHSS score, private insurance, cardioembolic stroke subtype, and reperfusion therapy, the lowest quartile of TSH was associated with non-ambulation at discharge (adj. OR 1.82, 95% CI 1.10-3.03). At 3-months, ln(TSH) was associated with Neuro-QOL upper extremity (adj. beta 0.98, 95% 0.11-1.85) and cognition T-scores (adj. beta 0.81, 95% 0.07-1.55) but not lower extremity T-scores (p=0.410) and 3-month mRS (p=0.453). Conclusions: Lower TSH levels are associated with more severe strokes, non-ambulatory status at discharge, and worse upper extremity and cognitive HRQOL scores at 3 months. The mechanism by which thyroid function alters stroke outcomes is unknown and requires study.